Abstract: An arc tube body 20 and a foil such as molybdenum foil 30 are joined with each other such that a compressive stress of 105 N/m2 or more remains at an ordinary temperature in the arc tube body 20 along a junction surface. The compressive stress is always generated on the arc tube body 20 even if a fluctuation in the stress is caused on the junction surface by the repetition of the ON/OFF of the arc tube (or a tensile stress is caused to have a very small value even if the compressive stress and the tensile stress are alternately generated). Thus, the junction strength of both members may be increased. In one embodiment, a plurality of cracks (intercrystalline cracks) may be generated on the molybdenum foil 30 by a high pressure acting during pinch seal, and quartz glass is caused to enter the cracks so that the junction strength of both members can be increased.

Abstract: An arc tube, which is capable of prolonging the life thereof by preventing occurrence of a leak caused from a crack of an arc-tube body, has the average surface roughness of each of outer surfaces 26Aa and 26Ba of tungsten electrodes 26A and 26B pinch-sealed to pinch seal portions 20b1 and 20b2 on the two sides of a light-emission tube 20a of an arc-tube body 20 is set to be 3 ?m or smaller. Thus, the state of pinch-sealing of the tungsten electrodes 26A and 26B to the pinch seal portions 20b1 and 20b2 is brought to a state in which the two elements are engaged with small pits and projections. Therefore, great compressive stress is not left in the region adjacent to the joint surface between the pinch seal portions 20b1 and 20b2 and the tungsten electrodes 26A and 26B as distinct from the conventional structure. In a case where a crack of the arc-tube body 20 is formed owing to the residual compressive stress, the crack is limited to a local portion which is the region adjacent to the joint surface.

Abstract: An arc tube that effectively prevents a metal halide from being deposited in a light emitting tube portion, causing the change of a light emitting color or the generation of lighting failures in an arc tube. An axial distance L1 from a neck portion 20C of an arc tube body formed between a light emitting tube portion 20A and a pinch seal portion 24B of the arc tube body to a step-down plane portion 20Ba2 of each pinch seal surface 20Ba in a pinch seal portion 20B is set to 1 mm or less. During pinch seal, consequently, a sufficient pinching pressure is applied to a electrode 26, such as a tungsten electrode up to a portion close to a tip portion thereof. Thus, it is possible to reduce the volume of an almost wedge-shaped slit 24a formed around the tungsten electrode 26 on an end in the axial direction of a discharge space 24, thereby decreasing the amount of a metal halide deposited on the slit 24a.

Abstract: A method of manufacturing an arc tube having a light emitting tube portion, a first pinch seal portion, and a second pinch seal portion, all formed on a quartz glass tube. The first and second pinch seal portions are disposed on both sides of the light emitting tube portion. The quartz glass is provided almost vertically with the first pinch seal portion down. A thermal insulating plate is provided in a boundary position between the light emitting tube portion and a portion to be pinch-sealed in an outer peripheral space of the quartz glass tube. Liquid nitrogen is jetted from a cooling nozzle provided obliquely below the light emitting tube portion toward the same, thereby cooling the light emitting tube portion. The portion to be pinch-sealed is heated with a burner, and pinch-sealed with a pincher immediately thereafter.

Abstract: An arc tube and method for forming an arc tube in which an electrode assembly including a tungsten electrode and a molybdenum foil are joined together in a partially overlapped state and pinch sealed into a pinch seal portion of the arc tube body to suppress leakage due to peeling of the molybdenum foil and prolong the life period of the arc tube. An overlapped length L1 of a tungsten electrode and a molybdenum foil is set to be 2D≦L1≦0.8W with respect to the diameter D of the tungsten electrode and the width W of the molybdenum foil. In another embodiment, the distance L2 between the molybdenum foil and a discharge space is set to be B≦L2≦0.8A with respect to the width A and the thickness B of a pinch seal portion.

Abstract: A discharge bulb including: an arc tube having a light emitting portion constructed in a manner that a light emitting substance is enclosed therein by pinch-sealing the arc tube, and discharge electrodes are oppositely arranged therein; and a shroud glass tube hermetically sealing and covering the arc tube, so as to form a space between the shroud glass tube and the arc tube. And a water content or pressure of gas enclosed in the sealed space is specified.

Abstract: A method of manufacturing an arc tube for a discharge lamp unit, incorporating a primary pinch-sealing step for mounting an electrode assembly in an open end of a glass tube W with a chamber portion 12. The electrode assembly comprises an electrode rod 6, a connecting foil 7 and a lead wire 8 integrally connected in series. The electrode assembly is inserted into an open end of the glass tube W such that a leading end of the electrode rod projects into the chamber portion 12. A temporary pinch seal region L1 of the glass tube W is pinch-sealed such that a portion of the connecting foil that is connected to the lead wire is contacted by the glass tube W. A vacuum is maintained inside the glass tube and a main pinch seal region L2 of the glass tube is pinch-sealed such that a portion of the connecting foil connected to the electrode rod is contacted by the glass tube.

Abstract: The amount of a metal halide to be enclosed in a generally ellipsoidal discharge space 24 within a discharge vessel 20a is set in the range 0.006-0.01 mg per unit volume (&mgr;l) of the discharge space 24. If the amount is less than 0.01 mg/&mgr;l, the deposit of metal halide 32 on the inner surface of the discharge space 20a in its lowest position midway between the narrow end portions thereof will not cause “shunting” of the arc between the electrodes 26A, 26B. As a result, the arc is effectively prevented from fizzling out after the metal halide lamp is switched on. To ensure that the metal halide lamp produces the intended luminous flux and color of light, the amount of the metal halide to be enclosed in the discharge space 24 should not be lower than 0.006 mg/&mgr;l.

Abstract: An arc tube provided with a central sealed chamber 12, in which light-emitting substances are enclosed, having a pair of electrode assemblies disposed opposite to each other. The electrode assemblies are sealed in pinch seal portions 13. The arc tube incorporates a residual-compressive-stress layer 16 formed on a surface of the glass layer 15 in each of the pinch seal portions 13 that contacts the electrode rod 6 included in each electrode assembly. The residual-compressive-stress layer has a length greater than or equal to 30% of the axial length of a glass layer region that only contacts the electrode rod 6 and/or an angular range greater than or equal to 180° in a circumferential direction of the electrode rod. Thermal stress (tensile stress) produced in the boundary between the glass layer 15 and the electrode rods 6 after the arc tube 10 has been turned on is absorbed and dispersed by the residual-compressive-stress layer 16 surrounding the electrode rods 6.

Abstract: An arc tube and method for forming an arc tube in which an electrode assembly including a tungsten electrode and a molybdenum foil are joined together in a partially overlapped state and pinch sealed into a pinch seal portion of the arc tube body to suppress leakage due to peeling of the molybdenum foil and prolong the life period of the arc tube. An overlapped length L1 of a tungsten electrode 26 and a molybdenum foil 30 is set to be 2D≦L1≦0.8 W with respect to the diameter D of the tungsten electrode 26 and the width W of the molybdenum foil 30, whereby occurrence of peeling of the molybdenum foil 30 is effectively suppressed while effectively suppressing occurrence of breakage of the molybdenum foil 30. In another embodiment, the distance L2 between the molybdenum foil 30 and a discharge space 24 is set to be B≦L2≦0.

Abstract: An arc tube body 20 and a foil such as molybdenum foil 30 are joined with each other such that a compressive stress of 105 N/m2 or more remains at an ordinary temperature in the arc tube body 20 along a junction surface. The compressive stress is always generated on the arc tube body 20 even if a fluctuation in the stress is caused on the junction surface by the repetition of the ON/OFF of the arc tube (or a tensile stress is caused to have a very small value even if the compressive stress and the tensile stress are alternately generated). Thus, the junction strength of both members may be increased. In one embodiment, a plurality of cracks (intercrystalline cracks) may be generated on the molybdenum foil 30 by a high pressure acting during pinch seal, and quartz glass is caused to enter the cracks so that the junction strength of both members can be increased.

Abstract: A method of manufacturing an arc tube for a discharge lamp device. The method comprises: inserting a first electrode assembly having an electrode, a molybdenum foil and a molybdenum lead wire connected integrally in series from a first open end of a glass pipe for the arc tube having a swollen chamber portion formed in a middle part in a longitudinal direction such that a tip of the electrode of the first electrode assembly is protruded into the chamber portion; introducing an antioxidant gas from a second open end of the glass pipe into the glass pipe; inserting the first open end of the glass pipe into a gas chamber to which the antioxidant gas is to be supplied; and pinch-sealing a first region including the molybdenum foil of the first electrode assembly in the glass pipe for a primary pinch seal with holding the first open end of the glass pipe in an antioxidant gas atmosphere.

Abstract: An arc tube that effectively prevents a metal halide from being deposited in a light emitting tube portion, causing the change of a light emitting color or the generation of lighting failures in an arc tube.

Abstract: The pinch-sealing for the first one of a pair of molybdenum foils is not performed by flowing inactive gas within a quartz glass tube like the prior art but performed in a manner that the lower end portion of the quartz glass tube 4 is sealed, and then and a pinch seal estimation portion 4b is squeezed by a pincher while air within the quartz glass tube is exhausted from the upper end portion thereof so that pressure within the quartz glass tube becomes in a negative pressure state of 100 torr or less and while heating the pinch seal estimation portion 4b. Accordingly, at the time of the squeezing, the inner wall surface 4c of the pinch seal estimation portion 4b thus heated is attracted to the molybdenum foil 12 side thereby to form fine concave and convex portions on the interfaces between the molybdenum foil 12 and the quartz glass tube 4, so that the molybdenum foil and the quartz glass tube are placed in an engaged state and the contact area therebetween is increased.

Abstract: A discharge bulb including: an arc tube having a light emitting portion constructed in a manner that a light emitting substance is enclosed therein by pinch-sealing the arc tube, and discharge electrodes are oppositely arranged therein; and a shroud glass tube hermetically sealing and covering the arc tube, so as to form a space between the shroud glass tube and the arc tube. And a water content or pressure of gas enclosed in the sealed space is specified.

Abstract: An electric discharge lamp apparatus which incorporates an arc tube 10 structured such that an enclosed glass bulb 12 of an arc tube body 11 is enclosed in an ultraviolet-ray shielding globe 20 and having a front end which is supported by a metal lead support 36 forwards extending from an insulating plug 30 provided with a focusing ring 34 and made of synthetic resin and which has a structure that a rear end of the globe 20 of the arc tube 10 is supported by a metal support member 50 secured to the insulating plug 30, wherein the metal support member 50 is constituted by a metal base plate 51 secured to the insulating plug 30 and forming a reference plane f2 running parallel to the focusing ring 34 on the front surface of the insulating plug and a metal vertically-holding member 60 (a slide plate 61 and an arc-tube holding band 71) integrally joined to the metal base plate 51 and arranged to vertically hold an electrically-discharge axis L of the held arc tube 10 with respect to reference plane f2 of the meta

Abstract: An electric discharge lamp apparatus incorporates: a metal lead support 36 which projects over the front surface of an insulating plug 30 made of synthetic resin, which supports the leading end of an arc tube 10 and which serves as a passage for electric power arranged to be supplied to the arc tube 10; and an insulating sleeve 38 which is made of ceramics formed into a pipe shape and through which the lead support 36 is inserted, wherein a predetermined gap S2 is provided between the insulating sleeve 38 and the lead support 36. Thus, insertion of the lead support 36 into the insulating sleeve 38 can easily be performed, and a dimension error of the insulating sleeve 38 can be absorbed. Since a bent portions 36a is provided for a portion of the lead support 36 into which the insulating sleeve is inserted, the insulating sleeve 38 and the lead support 36 can hermetically integrated with each other. Thus, rattle of the insulating sleeve 38 with respect to the lead support 36 can be prevented.

Abstract: An insulating plug for an electric discharge lamp apparatus, includes: a front portion includes an outer cylindrical portion and an inner cylindrical portion, the inner cylindrical portion having a substantially unique thickness and an opening to receive an arc tube of an electric discharge lamp; a focusing ring extending from the outer cylindrical portion of the front portion; and a rear portion having a rear-end cylindrical portion and a center portion. The front portion, the focusing ring and the rear portion are integrally molded by injecting a synthetic resin into a mold from a gate of the mold, the gate facing the rear-end cylindrical portion of the rear porition of the insulating plug. Furthermore, the electric discharge lamp apparatus in which an arc tube is inserted into the opening of the insulating plug described above.

Abstract: A metallic halide lamp has an envelope of silica glass defining a discharge chamber with a pair of pinch seals extending in opposite directions therefrom. A pair of tungsten electrode stems are partly buried in the respective seals and electrically connected to a pair of molybdenum lead wires via a pair of molybdenum foils which are wholly embedded in the pinch seals. The molybdenum foils have a recrystallization grain size of not more than about 50 .mu.m.